FlashBazbo

I'm a long-time Stages power meter user. I've used them on a variety of bikes (road and gravel, carbon and titanium, Shimano and SRAM) for several years and (except for a bad 1st generation battery cover) I've never had a moment's problem with them. Data has been reliable and consistent. I've been a big fan of the product.

But about three months ago, I started getting data drop outs from the Stages on my road bike. I don't think it's my Garmin's fault because the same Garmin, mounted in the same location, still works perfectly with the Stages on my gravel bike. Stages says it's not a signal problem -- they tested my PM after I returned it and it's transmitting about 10 feet. The replacement PM has the same problem -- still dropping data on the road bike but working perfectly on the gravel bike. Tracing back to "what changed?" for the road bike, the ONLY change I've made within a week or two of noticing the data problems is that I switched the aluminum wheels on my road bike for carbon wheels.

I'm still working with Stages to figure out what's causing the problem. Their customer service is excellent. They are working hard on the problem. But I thought I would ask here . . . Has anyone else had problems with data drop outs using Stages with carbon wheels (not including the 1st generation battery door problem)? Could it be that my Stages/Garmin combo were using my aluminum wheels to bounce the signal? How likely is it that the change in wheel materials caused the problem?

Seattle Forrest

I seriously doubt it. I would expect carbon to be less opaque than aluminum for the signal, but I don't really know.

topflightpro

I was having issues with data drops to my PC8 about a year ago. It turned out that the cheap, generic K-Edge GoPro mount I was using caused interference. Once I removed that, everything worked great.

kc0bbq

It's starting to look to me that my Garmin HRM and the Stages PM don't play well together. If I wear my HRM I get significant amounts of drops.


I should swap out HRM transmitters to see if that makes any difference, it might be misbehaving. If I broadcast HR from my Fenix 3 I don't seem to have issues, but optical HRMs don't work well with my wrists and the numbers are pretty inaccurate.

FlashBazbo

That would surprise me. I've been using Garmin's HRM straps all along and haven't had any interference on the gravel bike or, previous to this, on the road bike, either.

kc0bbq

The transmitter has lived a hard life, and if it turns out to be the case I couldn't really pin it on Garmin. There's a lot that could have happened to mess up some filtering or whatever. I use a Polar strap with the Garmin transmitter because I have a terrible history with their straps failing, but that shouldn't really affect things much.


The correlation has only clicked recently. On their own the HRM and the PM behave themselves. I usually don't bother with the HRM outdoors, just in winter training, and I've been blaming the drops on wifi, 30 bikes with a bajillion sensors in close quarters, etc., but on that last hill repeat night I was off on my own when the drops were at their worst.


The two rides since had no drops in 8 hours, on routes that included the same road we use for the repeats.


It's been a pain to figure out. It's crossed two different Stages PMs (Ultegra and Rival), both versions of the meter...

Seattle Forrest

My Fenix 3 HR can read my heart rate using the optical wrist sensor, even when it's in my pocket. It's more of a random number generator than a sensor.

Apologies to Bazbo.

kc0bbq

Mine is a strange mix of 33% matching a chest strap meter exactly, 33% random numbers, and 33% 'Are you sure you're actually alive?', and 1% OMG I CAN'T COUNT THAT HIGH.

JohnJ80

Look at the Scosche Rythm+. It's optical but you mount it on your upper arm over the brachial artery. Can't imagine you'd have a problem there - lots of signal. FWIW, I use a Garmin Edge 1000 or a Wahoo Elemnt with a Stages power meter on a K-edge mount and a Scosche Rythm+ HRM with carbon wheels with no problems.

As an aside, I have had a sensor that used a Nordic Semiconductor chip (apparently pretty common device for ANT+ and BTLE sensors) conflict and screw up sensor information into my Garmin Edge 1000. So I wouldn't be at all surprised to see a HRM causing a problem. At some point, these "personal networks" that are starting to get kind of complicated are probably just ripe for network interference or network conflicts.


J.

Seattle Forrest

lol. I use a chest strap for important stuff like intervals, too.

hueyhoolihan

i suppose it's possible that the metal rims where enhancing the signal in some way, just a WAG, and now without them...

i think i'd put the metal rims back on, if practicable, and see what's what.

joejack951

Classic.

BTSyndrome

My Garmin 520 has to be on top of the stem to read the Stages perfect...(every bike I have)
If it's on an out-front mount it will randomly drop out. Would I like it farther out front? Sure.
But I'm just glad my Stages is working and lasting as good as I hoped when I picked it up on clearance for $369.00

Silvercivic27

Maybe static electricity from the carbon

Heathpack 

I had a total of 5 Stages power meters (two meters: one refurbished once and both replaced once, to yield 5 total PMs used over a year). Endless data dropouts for a year. Much trouble shooting with both Garmin and Stages. Wound up testing a total of 4 Garmin units- 3 Edge 510s and one Edge 1000- on three different bikes. Nothing helped with the data dropouts expect replacing the Stages with SRMs. Once I did that, instantly every problem I had ceased.


I don't own any carbon wheels.


Stages units just send out very week signal compared to the SRM- this has to do in large part I believe to the robustness of the batteries in the different products. (Yes I know about the battery doors- replaced them many times.) My coach's comment was that in addition to the Stages' sending out weak data signals, the Garmin's software is very "emotional"- any little glitch in the data the Garmin gets tends to cause a reaction in which the unit effectively throws up it hands and refuses to play any more with the power meter.


I know there are a good number of people who have no issues with their Stages. But my experience is that what you're seeing is common with Stages, its inherent to the product. You will just go through endless loops of troubleshooting with no solution to your problem. (I hope I'm wrong, of course.)


Stages was always easy to work with, though, I will give them that. And in the end, they gave me full refunds for both units after 1 year of troubleshooting. So they are a class act that just happens to make a flaky product.

FlashBazbo

I hear you, Heathpack, and I'm one of those who, until now, has been a very satisfied user. Over the years, I've used several brands of power meter and Stages was my best experience, to this point.

I never used an SRM, though. Even when they were new tech, I couldn't get past the weight and the requirement to send in the meter to have a battery replaced. They were certainly the "gold standard" back in the day.

smarkinson

Why not melt some aluminium in your home forge and then pour it into the carbon wheels filling the cavity in the rim.? Best of both worlds, RF signal bouncing and aero.

Seattle Forrest

Do you still have your old wheels? Can you put them on for a day and find out?

Heathpack 

Well the batteries last 5 years nowadays, and it helps having more than one power meter so that you're not out of business during the few days every 5 years that your SRM is out getting a new battery soldered in place. I'm also pretty sure my husband could do the battery swap when the time comes. He'll just have to talk to SRM and see what that does to the warranty.

If it comes to that, the price of new SRM units has come down substantially and now they even come with a lifetime warranty.

As to weight, I can't really comment on that, I never looked into it. But I do know coach used SRM meters even when he was a skinny climbing guy, competitive in really tough fields. He wasn't worried enough about weight to use something else. My basic MO is to just emulate worrying about the same things he worries about, it's more efficient for me that way...

Kopsis

More likely than you might think. RF design is hard. You have to deal with co channel interference (other transmitters on the same frequency), adjacent channel interference (other transmitters on slighly higher/lower frequencies), and multipath interference (your own signal getting reflected back). In the case of a crank arm PM, you need to deal with a very small antenna, and very little battery power (which limits the amount of signal processing you can do). Then, because all that wasn't hard enough, put your antenna on a metal arm and spin it at 90 RPM where every revolution it passes close to a wheel full of metal spokes spinning at 250 RPM. It's kind of amazing these things ever work.

Without supercomputer-class RF modeling, there's no way to say what it is about the change that's causing a problem. And Stages static testing TX power isn't going to tell them anything. Without the ability to instrument and test in your exact configuration, any attempt at tuning would just be guess work.

Short of getting a different PM, you could try moving your Garmin. The wavelength of 2.4 GHz in air is about 125mm, so moving from an out-front mount to a stem mount (or vice versa) may actually be enough to put you in an better spot in the interference pattern. Even a small shift left or right with a bar mount might help (and doesn't really cost anything to try).

FlashBazbo

I THINK I have my answer. With aluminum wheels, I used an out-front mount for a couple years with perfect performance. With carbon wheels, I suddenly had drop-outs using the out-front mount. Today, I mounted the Garmin on the stem (and kept the carbon wheels) and went out for a ride. No drop outs. Strong signal. Perfect performance. Even the calibration process went a LOT more quickly.

I don't think Stages is allergic to carbon wheels. I think it's probably allergic to out-front computer mounts (as at least one poster in this thread has mentioned). My aluminum wheels were just the crutch Stages needed to work with an out-front mount. That's my theory, at least.

At any rate, the setup works well with the Garmin mounted on the stem. I will have to grow accustomed to looking farther down at my computer -- but it looks sleeker there, anyway. (If you can't BE fast, at least LOOK fast.)

Seattle Forrest

A Garmin definitely looks better on the stem than on an out front mount.

And you just shaved 12 grams off your bike.

Seattle Forrest

How much does that cost?

I'm curious because Beth made me get a PLB a couple years ago. It's the same story, the battery is good for 5 years, then you have to send it in to have the battery replaced. The consensus is you're better off buying a new PLB when your 5 years are up.

Heathpack 

No idea what it costs but I don't think its prohibitively expensive. One strategy to consider is to sell the meters used while they still have some battery life left and roll that $ into the purchase of new meters since now they come with the lifetime warranty which is worth having. That math will depend on what they are selling for new and used at the time, I have a 2-3 years still before this is an issue. I ride shorter cranks than most people, so my SRM meters are a little rare on the used market which means I might get a better price for them.